As the name suggests, PVC processing aid is a product that helps PVC processing. Its use can make our processing better, but what are its functions? What is a principle of action we are using it for? Here we take a look.
Due to the poor ductility of the melt of pvc, it is easy to cause the melt to be broken, and the pvc melt is relaxed, which can easily lead to the defects of rough and dull surface of the manufactured articles. Therefore, in order to improve the defects of its melt, PVC processing aids are often added when processing PVC. There are three main modes of action of processing aids: promoting resin melting, improving melt rheological properties, and imparting lubricating properties.
Promote resin melting: When the pvc resin is heated and melted under a certain shear force, the processing aid is first melted and pasted on the surface of the pvc resin particles, which increases the viscosity and friction of the pvc, and effectively transmits the shear force and heat. , to accelerate the melting of pvc.
Improve melt rheological properties: PVC processing aids can improve the flow properties of PVC such as poor melt strength, poor ductility and melt fracture. The principle is to increase the viscoelasticity of the pvc melt, thereby improving the die expansion and increasing the melt strength.
To impart lubricity: First, let the processing aid and the pvc-compatible part melt to promote the melting effect, and the non-pvc-compatible part migrates out of the molten resin system, thereby improving the mold release.
From the above introduction, we can also see a principle of action of PVC processing aids. They play a lot of roles in their processing. Our processing is inseparable from it over time, but we still have to choose well when using them. product, use it correctly.